Why do our eyes have colour? I read in a magazine blue is the most common eye colour closely followed by brown then green. Do you think blue eyed people have advantages over brown or green eyed people? (just wondering)

I´ve heard somewhere that blue-eyes let in more light and so they see better in darkness. Brown-eyes is not so easily offended by bright light though, such as the sun, and so has an easier time seeing in bright light.

When talking about genes though, blueeye-gen is "weaker" than browneye-gen, mening the chances of getting brown eyes are bigger. Green-eyes have the same basic gen as brown-eyes, but how that works out I have no idea. Really most common with blue eyes??? I had no idea...

In a brown eye there is a lot of melanin in the anterior border layer. This absorbs the light and gives a brown velvety appearance.

In a blue eye there is not much melanin in the anterior border layer. The light passes into the stroma where the collagen fibres scatter the light back as blue.

In a green eye (or a hazel one) there is a variable level of melanin, so that some of the light is absorbed by the melanin and some is scattered by the collagen. The brown layer looks yellow as it is thinner, and so the yellow and blue mix to make green.